Right now, Streeme only accepts MP3 and OGG files. I'm working on
making more converters and supporting more filetypes, but for now, you
can click convert to mp3 in iTunes and those will scan as expected.
Streeme uses the Location tag in the XML file for paths, there is a
secondary stage that tries to determine if the file still exists and
if it's a compatible file type. You shouldn't move the iTunes XML file
around if possible. iTunes writes to it when you add new music. If you
need different paths than iTunes provides, you should use the
filesystem scanner.
-Rich